1. Field of the Invention
The present invention relates to a self-aligning roller bearing.
2. Description of the Related Art
A conventional self-aligning roller bearing described in, for example, Japanese Patent Application Publication No. 2016-191429 (JP 2016-191429 A) has been known. The self-aligning roller bearing includes, for example, an outer ring 81, an inner ring 84, spherical rollers 86, an annular cage 88, and an annular guide ring 90 as illustrated in FIG. 5. The outer ring 81 has an outer raceway surface 82 formed on its inner periphery. The inner ring 8 has two rows of inner raceway surfaces 83 formed side by side on its outer periphery. The spherical rollers 86 are disposed in two rows side by side between the outer raceway surface 82 and the inner raceway surfaces 83. The cage 88 holds a plurality of spherical rollers 86 in each row. The guide ring 90 is disposed between the cage 88 and the inner ring 84 and disposed between the two rows of the spherical rollers 86. The cage 88 is positioned in a radial direction by the guide ring 90.
In the self-aligning roller bearing illustrated in FIG. 5, the spherical rollers 86 rotate about virtual lines L1 (as indicated by arrows r1 and r2) that pass through contact points P1 and P2 at which the spherical rollers 86 contact the outer raceway surface 82 and the inner raceway surfaces 83.
As a result, the spherical rollers 86 may be skewed. In this case, end surfaces 86a of the spherical rollers 86 may contact outer surfaces 90b of the guide ring 90, or the guide ring 90 may be sandwiched between the spherical rollers 86 disposed on both sides in the axial direction. The guide ring 90 is generally formed of a material with hardness lower than that of the spherical rollers 86. Thus, problems such as wear of the guide ring 90 may arise due to contact between the guide ring 90 and the spherical rollers 86.